Quantitative properties of sovereign default models : solution methods matter

Author/Editor:

Leonardo Martinez ; Horacio Sapriza ; Juan Carlos Hatchondo

Publication Date:

April 1, 2010

Electronic Access:

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Disclaimer: This Working Paper should not be reported as representing the views of the IMF.The views expressed in this Working Paper are those of the author(s) and do not necessarily represent those of the IMF or IMF policy. Working Papers describe research in progress by the author(s) and are published to elicit comments and to further debate

Summary:

We study the sovereign default model that has been used to account for the cyclical behavior of interest rates in emerging market economies. This model is often solved using the discrete state space technique with evenly spaced grid points. We show that this method necessitates a large number of grid points to avoid generating spurious interest rate movements. This makes the discrete state technique significantly more inefficient than using Chebyshev polynomials or cubic spline interpolation to approximate the value functions. We show that the inefficiency of the discrete state space technique is more severe for parameterizations that feature a high sensitivity of the bond price to the borrowing level for the borrowing levels that are observed more frequently in the simulations. In addition, we find that the efficiency of the discrete state space technique can be greatly improved by (i) finding the equilibrium as the limit of the equilibrium of the finite-horizon version of the model, instead of iterating separately on the value and bond price functions and (ii) concentrating grid points in asset levels at which the bond price is more sensitive to the borrowing level and in levels that are observed more often in the model simulations. Our analysis questions the robustness of results in the sovereign default literature and is also relevant for the study of other credit markets.

Series:

Working Paper No. 10/100

Subject:

English

Publication Date:

April 1, 2010

ISBN/ISSN:

9781451982770/1018-5941

Stock No:

WPIEA2010100

Price:

$18.00 (Academic Rate:$18.00)

Format:

Paper

Pages:

28

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